Apparatus for firing dehydrating plants and for cooling the product



Sept. 12, 1950 J. cl BYERS Y APPARATUS FOR FIRING DEHYDRATING PLANTS AND FOR eoeunc PRODUCT Filed-Mann 14,1949

5 r M 6 v a m Patented Sept. 12, 1950 j UNITED. TVSTATE ."APPARATUS on FIRING, lamina! ING PLANTS AND FOR PRODUCT COOLING THE f.

' :Ju'aii, C. Byers, Kansas City, Mo;, assignorto Butane Motor Fuel Company, Kansas City, Mo.,

a corporation of Missouri Application March 14,1949, Serial Noi 81,313

uid content, for subsequent storage or packaging for use in a relatively dry condition.

It is well known by those skilled in the field of dehydration, particularly with respect to 3,111?- mal feeds such as alfalfa and other leguminous.

products, that the conventional procedure of heating the crop to remove its water content results in subsequent storage of thefinished product in a heated condition with a consequent loss in food.

value, particularly its carotene and vitamin A content while such productis so stored, which losses are, to an appreciable extent, caused by the product remaining in such heated condition prior to use. v

It is'one of the most important objects of this invention therefore, to provide apparatus for use by and in connection with a, conventional. dehydrating plant capable of automatically and inexpensively lowering the temperature of the finished product, prior to storage or packaging thereof, to the extent necessary to cause the finished product to retainits carotene and vitamin A content and other food values until consumed, depending of course, on storage conditions used.

Another important object of the present invention is to provide apparatus capable of accomplishing the results just above mentioned and also operable to utilize liquid, combustiblehydrocarbons in firing a vaporous: gas burning furnace forming a part of the dehydrating plant, the apparatus being soformed and arranged as to include the necessary liquid vaporization step.

by use of heat emanating from the material lt-. self, all to the end that the actual fuel consumption is reduced appreciably.

Itis seen from the foregoing therefore, that it is. the primary object of the present invention to provide apparatus capable of utilizing liquified petroleum gas for firing the furnace of a dehydrating plant and also for cooling the prodnot that is produced by said plant, the apparatus,

16 Claims. (on. 263- 1)? liquid isreleased thereinto under pressure augmenting vaporization, by the product itself.

Asstill further object of the present inventionis to provide apparatus as above set forth wherein a coolant is continuously circulatedaround the aforesaid vvaporizer in heat exchange relation-"- for ship thereto and wherein the heated product emanating from the dehydrator i'sbrought into heat exchange relationship with such coolant, all

,to the end that the product itself is automatically lcooled and the vaporizer is automatically heated to induce vaporization of the liquid fuel. Other important objects will be made clear'or;

become apparent as the following specification progresses, reference being had to the accompanying drawing, wherein: r

The single figure shows diagrammatically a dehydrating plant having apparatus for utilizingv liquified petroleum gas for firing the furnace the plant itself, all made in accordance with my present invention.

Various f means thereof and for cooling the product produced by have heretofore been provided" 2 r for cooling'food products emanating from ade hydrating'plaLiitto a sufficient degree to insure retention. ,of carotene. and vitamin A content in the finished product, which include refrigerating structures having means for bringing the heated product into heat exchange relationship with a coolant; "Virtually all of such previously disclosed deviceshave been impractical however,

particularly in' the dehydration of feed for farm animals' such as alfalfa and the like, because of the fact that such a large volume of the feed is handled-by the plant, resulting in considerable expense in the operation of the refrigerating structure itself. 1

Itis also appreciated-that liquified petroleumgas and other-combustible hydrocarbons, have" heretoforei'been used in dehydratin plants for firing the furnace thereof and that Vaporizershave been used to convert such liquid to a gaseous form. However, here again to attain complete the 01 with the lowing "specification, that I have combined the productcooling structure with the means for vaporizing-the fuel itselfyall capable of reducing fuel consumption drastically and coolingthe fin'- ished product to desired.

Inthe drawing, there is illustrated a conventional dehydrating plant'which includes an elonrelatively low temperatures if" gated, cylindrical drum I0, mounted on rollers {2 for rotation on a substantially horizontal axis and motivated by any suitable prime mover, not

shown. It is appreciated that the particular type of dehydrator that is used is immaterial to the present invention butin all plants I of v this. character, the'rfeis providedjmeans such' as' a furnace l4 for applying heat to the liquid containing product to be dehydrated. Such heat is directed into the rotating drum HJ through the medium of a conduit l 6 and there is alsopr'o'videdan inlet opening in the drum not shown, forintr'oducing the product itself thereinto. Drum I is also obviously provided with an outlet ppening for the dehydrated product that empties'iiitoa suitable blower !8 that forces the heated product upwardly through a conduit 2U. Conduit-2llempties into a cyclone separator 22 and the product moves by force of gravity through the open bottom of separator 22, through a conduit 24 and into another blower 26. veyed upwardly by: blower- 26 through-a conduit 28-for dumping into second cyclone sepa'rator 3.0, wh'ereupon'the product-passes bys'f-orce of' gravity outwardly from theiseparator 3fl thr'ough a pipe 32 and into a conventional grinder or hammer mill 34.

Hammer mill 34 is equipped with means for forcin the groundproduct. upwardly through a pipe 3tand into a collector 38- where the prod uct falls by force of gravity downwardly through aconduit 4t and into a waste heat boiler; broadly designated bythe numeral '42 and hereinafter to be more fully described. I

The structure just abbve'des'cribed is for' illus-' trative purposes only and' obviously, in some dehydratin plants moretha'ntwo cyclone separators are used and' oftentimes a plurality of' hammer mills 34, as well'as a like number of 1 collector's 38'; are provided. In other cases'there' is provided pellet forming apparatus and hammer mills are not used. Such multiplicity of p'a'rt's hasno' bearingjon the present inventionand it will be appreciated upon understanding the principles'hereof, that the same can be applied ir respective of the precise. arrangement of the plant'itself. I

This invention contemplates the use ofa liq-. uid'fnel for firing the furnace such as a combustible hydrocarbon in cluding butane or anyother liquified petroleum gas. vThisliquid-fuel is stored within a container 44- under: pressure;

as is a pressure regulator 54 between valve52 and heat exchanger 46.- The outlet end of the coilswithin the heat exchanger H3 communi cates with a conduit ESth'at communicatesdi rectly with furnace I 4 in theusual manner;

A liquid trap 58 is'int'erposed'in the-line '56 together with a pressure regulator 60 next adjacent the: furnace I 4 and a control valve 'B2*isin the line 56' between trapx58 and. the pressure regulator" 60; Each ofthe cyclone-separators 2-2 and and the collectortll is provided, with a hollow-closedchamber designated by the numerals 64, 66 and 68 respectively. These said cham-bers are'formedby a double wall con struction in; the separators-Hend- 30 andthe-- The product is: again con-" Til ' outermost walls of container l6.

4 collector 38 as illustrated, taking the form of jackets 10, 12 and 14 respectively.

The waste heat boiler 42 includes a hollow container 16 havin an inlet spout 78 at the uppermost end thereof, communicating with container 'lfiand disposed to receive the heated prodtlcite'manating from the'pi'pe 40.11

The lowermost end of the hopper-like con- -tainer I6 is provided with an outlet opening and the product within container It is moved through such outlet and into sacks or other containers or the vehicles for conveying the product to a point of storage, through use of an auger-type conveyor 88 Container 42 is completely covered by a jacket-82 defining a space 84 around the Container 16 also has mounted therein a hollow receptacle 86 in any suitable manner and in spaced relati'o'nship to all walls thereof.

A plurality of agitators Ell! within the container '16; all disposed in spaced relationship to the walls of container 16" and to the hollow body 86, serve to agitatethe product within the waste heat boiler 42 for purposes hereinafter to be made- All of the compartments 54'; 65, 88 and 84; as well as the hollow body 85,-are in direct communication Withthe tank'AB of heat exchanger: through a conduit system shown in the draw-' mg... l

Tank 48' has anoutletconduit 92. provided with a branch .ottha-t communicates with the lower-' most end of: the compartment of separator 22. A liquidcoolant such as abrine, is con-" tained within the tank' 48 and. within the con-- duits: and compartments connected therewith, such'. coolant that passes into the branch 94' emptying into a surge tank 96 interposed in branch 94-. A liquid pump 913 within branch 94 draws the'liquid fromtank 48 through line 92" and branch 94* for emptying: into the compart ment'64. Y

.A second branch Hi0 hasa "surge tank H32 and a liquid pump Hand-connects directly with the lowermost end of compartment-66*of'sepa rator 3t. A third branch lflthas a surgetan'k 108* and aliquid pump H8 and communicates"- with the compartment? 34 of waste heat boiler 42' at thelowermost end thereof. The main outlet1ine92 of-heat exchanger 46. communicates with the; lowermost'end of the compartmentfifl' of collector 38 and has interposed therein a surge tank H2 and-apumpl M.

Control valves- HS; H8-'and 12B areprovided in the brancheszim; lilO' and lllt'respe'ctively and thekmain line 92 "has a control valve 122 disposedbetween branch IDS-and thesurge tank H2. The 1 tan-k 48 0f the'hea't exchanger 46 1s also pro vided with a main inlet'line I'M that connects directly with the uppermost end cr me compartment -84--o'f boiler t2: Branches I26; 528- and I30 provided withcontrol valves I32; 434 and 136 respectively, interconnectth'e main inlet'line H l -for tan-l: 48 with the uppermost ends of the compartments 6%; 6G and 68 respectively; 'Line' i24 is also provided with a control valve l38 be tween the branch 136- an'd'the boiler 32'.

Branch-106 communicates directly with body lit-by a conduitsll, and'body-BB empties directly into line I24 by a conduit 89.

Itis clear fromthefforegoing that with all of thevalves H6; H8; I20; i22 132, I3 3, i36 andl38-"open'and with all pumps 98, 1M; H9 and l M operating, the fluid within tank in ..which' the coils therein-are -immersed,- will bezeaasaa circulatedoutwardly... as indicated by-i arrows through line 92 and itsbranches;,$l4., ;III0, and

I06. Such fluid will pass into the compartments,

64, 66, 68, 84-and86 and returnntorthexta by .Way'of line I24and -its..branche s I25, I28 and I30. The hot dehydrated material. passing;

through the separators 22 and 30, collector 38,

and boiler 42, will, move into heat. exchange re lationship with the circulating-brine and as such;

liquid brine emanatesfrom the-tank 48 in ;a

cooled condition, the temperature; oflthe product will consequently be lowered. Asthe circulating, liquid coolant absorbs heatfrom the dehydrated material, its temperature will be raised and,consequently the liquid passing into tank .48, by way of .line- I24, will have an appreciablyihigher temperature than its temperatureas the same passes from the tank 48.: This changeoftemperature of the coolant within the heat exchangerdji, is caused by the passage of the liquid fuel-from the tank 44 under pressure into the coils within heat exchanger 46; the heated, coolant entering.

tank 48 and traversing the coils therewithin will, through heat exchange relationship with the vaporizing fuel within such coi1s,-augment vaporization of the liquidfuel and such. vapor-, ized gas will pass. into the furnace I4 by way ofv line 56. Obviously, the temperature of the finished product at the time the same passes from compartment I6, depends on the length of time the product is subjected to the coolant and it may be found that boiler 42 is unnecessary and that the compartments v64, 66, and;.68 will lower. the temperature of the finishedprod- 'uct sufiiciently to suit the desires of the operator. However, by permitting the product to dwell within the container I6 prior to actual discharge through use of-auger 80, it is possible to lower the temperature of the product to a relatively low degree andfurther, through use .ofthewasteheat boiler 42, the vaporization of the liquid fuel;

emanating from container 44.will;be morecomplete. It may be found therefore, that boilerv 42 will be the only device necessary toaccomplish the desired results. be controlled byuse of limit switches .of conventional character (not shown).v .to regulate the a be necessaryto insulate all of thelines'leading from and to the heat exchanger 46 aswell asthejackets I0, I2, I4 and 82. The choosing of such insulation, as well as. the choice of pumps 98, I04, H and I I4 will, to a great extent, determine the temperature of the finishedproduct and the amount of complete fuel vaporization that a s place. r .1

Another factor which determines; to ,a great; extent the temperature ofthe finishedproduct. and the amount of complete vaporizationof the liquid fuel is thepressureat whichsuch-liquid fuel is introduced into the coils of heat exchanger.

46. It is contemplated that suflicient, pressurewill exist in the tank 44 to lower; the temperature of the finished product well below that necessary" to maintain its vitamimll content and other Further, such dwelling can ,ra ues. du in pa ka ing and. storiria;

Through use of. the pressure regulator 44, such. temperature of the finished product camber-cone trolled. While the. relationship between the extentto which the dehydrated product is subjectedpto the coolant, and the pressure under which the liquid fuel is introduced to the heat exchanger, will determine the extent of complete fuel ,vaporization and the temperature of the finishedprode uct,,it is contemplated that if desired, the pres: sure of the liquid fuel as they same entersthe: heat exchanger .46, may be increasedthrough use of a compressor I40. Compressor I40 may. be..ofconventional characterandis interposedwithin .a by-pass I42, valved as'at I44and-l46 andiinterconnecting line 56 with a .branchpipe. I48 that joins tank 44 and main line 56.. Branch:

I48 is also provided with a valve I50'adjacentits,

connection with line 56. 'Through use. of com-.

pressor I40, it is possible to increasethe pressure.

ofthe liquid fuel, to further lower the tempera? ture of the finished product as desired. mm; It isbelieved that .it will be necessary;.when

using such compressor I40, to provide.-.a,.cone

denser I52..that may be water cooled through inlet and outlet pipes I54 and I56 respectively. Lines I54 and I56 have connection with a. source of coolant not shown, and may even: be connected with the heat exchanger 46 if desired Condenser I52 is joined with branch I48 through; a by-pass conduit I58, and a valve I60 in-branchv I48 may be closed to force the liquid emanating from compressor I40 through condenser I52. It is appreciated therefore, from the foregoing that the temperature of the finished produetiand.

the extent of complete vaporization of the liquid fuel'is dependent on a large number of factors including the over-all size of the dehydrating plant itself. It'is, therefore, difficult to' specify any certain temperatures or pressures, but it contemplated that with the proper choosing of heat exchanger46, with an introduction of the liquid fuel into the coils ofheat exchanger'w at 60 degrees Fahrenheit and with a pressure'of approximately 30 pounds per square inch tli'e coolant will emanate from tank 48 and pass into the conduit 92 at approximately 20 Iti's further anticipated that th coolant will re-enter the heatexchanger 46 at approximately "F; and that the finished product emanatingfrom' the container I6 willfbe lowered in temperature to approximately 30 to 40 F. Whether ;.ornot it will be necessary or desirable to lower the temj perature of the product to such extent,will'de.-' pend of course, upon the type of storage means for the product and whether or not the same'is itself insulated or otherwise formed to maintain the lowered temperature in the product so that the latter does not again reheat and thereby lose, its vitamin Ajfcontent. However, a relatively low; temperature in the finished product has no effect. thereupon and since vaporization of the liquid, fuel can be enhanced, such should be done to reduce fuelconsumption to as low a point as possible. a 3

"It is appreciated from the foregoing that the entire structure forming the subject matter her-ea of is automatic and when placed in operation, will not only lower the temperature of the fin:v ished product to a desired point, but. WillII-ESUJIJ in a tremendous saving in fuel consumption. Not only'will the furnace of the dehydrator workv more "efficiently to the end thatymore complete dehydration of-ithaproduct occurs,- but-the dam-.5;

vaporizer, said chamber being adaptedftdconone hollow compartment having connectiori'with said chamber; meansfor cidculating said coolant through the compartment and chamber; means for directing the heated material emanating'from the dehydrator against the outer surfaces -'of said compartment; and means for controlling the pressure of said liquified petroleum gas" as the same passes into the vaporizer wherebyto control the temperature of said coolant;

8. Material treating structure comprising a dehydrator for material to be treated, said dehydrator having a vaporized gas burning furnace for heating said material as the same passes through the dehydrator; a source of liquified petroleum gas under pressure; a closed passage connecting said liquified petroleum gas source with said furnace; aheat exchanger having a vaporizer interposed within said passage'for-receiving the liquified petroleum gas, and a chamber enclosing said vaporizer, saidvchamber being adapted to contain a liquid coolant for immersing said vaporizer; at least one hollow compartment having connection with said chamber; means for circulatingsaid coolant through the compartment and chamber; means for directing the heated material emanating from the Idehydrator against the outer surfaces of said'fcompartment; and auxiliary means for selectively increasing the pressure of said liquified petroleum gas prior to passage thereof into saidvaporizer whereby to lower the temperature of said coolant desired amounts.

9. In a material treating assembly having apparatus for heating the material as the same is treated, and including a furnace adapted to burn vaporized gas; means for utilizing the heat emanating from said material after the same passes from said apparatus to vaporize a liquified petroleum gas under pressure separate from said material for use by said furnace, said means comprising a heat exchanger having a chamber adapted to contain a. circulating liquid coolant and a vaporizer immersed in said coolant for receiving said pressurized liquified gas; a passage for connecting said vaporizer with said furnace; and structure for directing the heated material from said apparatus into heat exchange relationship with a portion of said chamber.

10. In a-material treating assembly having apparatus for heating the material as the same is treated, and including a furnace adapted to burn vaporized gas; a structure for automatically converting liquified petroleum gas under pressure separate from said material to gas vapor for use by said furnace and simultaneously refrigerating the heated material emanating from said apparatus, asid structure comprising a heat exchanger having a chamber adapted to contain a circulating liquid coolant and a vaporizer immersed in said coolant for receiving said pressurized petroleum gas; a passage for connecting said vaporizer with said furnace; a jacketed passage for receiving said heated material as the same emanates from said apparatus; and means for placing said jacket into communication with the chamber.

11. In a material treating assembly having apparatus for heating the material as the same is treated, and including a furnace adapted to burn furnace; a container for receivingthe heated ma-'-' terial from said-apparatus, said container having 'a closed compartment therearound; means placing said compartment into communication 'with "said chamber; and mechanism for circulating said coolant throughthe icompartment andthe chamber. v I

12; In a material treating assembly having apparatus for heatingthematerial as the sameis treated, and including a furnace adapted to burn vaporized gas; structure for automatically converting liquified petroleum gas under pressure to gas vapor for uselby said furnace and simultane ously'refrigerating the heated material emanating from said apparatus, said structure comprising a heat exchanger having a chamber adapted to contain a liquid coolant and a vaporizerim' mersed in said -coolant for receiving said pres surized' petroleum gas; a passage for connecting 's'aidvapo'rizer with said furnace; acont'ainerf or recall/mg" thaheatd ri l from said appa= ratus, said container having'a' closed'compart' ment therearound; means placing said compartf ment ilito' communication" with said chamber; mechanism for circulating said coolant through the compartment aand the-chamber; and-means for agitating said material in the container.

13. In a material treating assembly having apparatus for heating the material as the same is treated, and including a furnace adapted to burn vaporized gas; structure for automatically converting liquified petroleum gas under pressure to gas vapor for use by said furnace and simultaneously refrigerating the heated material emanating from said apparatus, said structure comprising a heat exchanger having a chamber adapted to contain a liquid coolant and a vaporizer immersed in said coolant for receiving said presverting liquified petroleum gas under pressure surized petroleum gas; a passage for connecting said vaporizer with s-aidfurnace; a container for receiving the heated material from said apparatus, said container having a closed compartment therearound; means placing said comp-artment into communication with said chamber; mechanism for circulating said coolant through the compartment and the chamber; and a closed, hollow body in the container imbedded within the material therein and having means for placing the same into communication with said chamber.

14. In a material treating assembly having a dehydrator for the material being treated provided with a material heating furnace adapted to burn vaporized gas, at least one separator for receiving the heated dehydrated material from the dehydrator, pulverizing means disposed to receive the material from the separator, and means for collecting the pulverized material; in combination, material cooling means including a hollow compartment for said separator and said collector respectively, each disposed in surrounding relationship to the flow of material, a hollow chamber adapted to contain a liquid coolant and communicating with said compartments, and means for circulating said cool-ant through the chamber and the compartments; and structure for converting liquified petroleum gas under pressure into vaporized gas-tier use-by said vt-um ar-ze,

,said structure including a vaporizer fol-receiving "said liquified gas through pressure and adapted for connection with the furnace, said yaporizer "being disposed within said chamber in immersed relationship with the coolant, Wherebythe vmaterial is cooled and the liquified petroleum gas is simultaneously vaporized as the coolant is circulated, as the material passes through the separator and collector, and asthe liquified gas passes to the vaporizer under pressure.

15. .In a material treating assembly having a dehydrator for the material being treated pro-- vided with a material heating furnace-adapted tcrburn vaporizedgas, at least :one separator for receiving the heated dehydrated material from thedehydrator, pulverizing means dispcsedrto receive thematerialvfrcm the separator, means for collecting the pulverized material, :and a container'for receiving the material fromvsaidcollector; in combination, material cooling means including a hollow'compartment for said separator, said collector and said container respectively, each disposed in surrounding relationship to-the flow of material, a hollow chamber adapted to I contain a liquid coolant and communicating withsaid-compartments, and means for-circulating said coolant through the chamber and the compartments; structure forconverting liquified petroleum gas under pressureiintoivaporized gas icruse by said furnace, said. structure including a vaporizer for receiving said liquified gasthreugh pressure and adapted for connection with the '12 rf-urnacaesaidivapcrizer being disposed withinasaid chamber in immersed-relationship with the coolrant, whereby I thelmaterial is cooled and the liquified petroleum;gas-is.-simu1taneous1y vaporized as the coolant-is circulated, as the material passes through the separator and collector, and as the *l'iquified/gas passes tothe vaporizer under pressure; and means tor agitating said material within the container to increase heatabsorption .by said cool-ant from: the material.

"16. ..App aratus for utilizing .liquified petroleum gas for firing furnace of a dehydrating plant adapted to burn vaporized gas and .fcr cooling the product produced bysaid plant, said apparatus romp-rising :a heat exchanger having a chamber adapted to contain a coolant and a vaporizer within the chamber; means for directing liquilied petroleum gas separate from said product into the -.vaporizerunder pressure; .struc tureior moving theproduct emanating from said plant into heat exchange relationship with a portion of saidichamber; and means for feeding vaporized gas from .saidvaporizerto said furnace.

- JUAN C. BYERS.

' "REFERENCES CITED The'following references are of record in the file of this patent.

' UNITED STATES PATENTS Number vName "Date 1,363,313 f Concver r Dec.,28, 1920 1,501,775 i-Iiller V v v July 15, 192,4 2,390,979 Young an Dec. .11., 194.5 

